Furnace.



H. E. WALLIS.

FURNACE.

APPLICATION FILED JAILB, 1907.

Patented Feb. 28, 1911.

5 SHBETSSHEET 1.

H. E. WALLIS.

FURNACE.

APPLICATION FILED JAN.8,1907

Patented Feb. 28, 1911.

5 BHEETs-SHEET 2.

H. E. WALLIS.

FURNACE.

APPLICATION FILED JAN.8, 1907.

5 SHEETSSHEET 4.

5111mm for Qqhfmcooc Patented Feb. 28, 1911.

H. E. WALLIS.

FURNACE.

- APPLICATION FILED JAN.8,1907. 95,4, Patented Feb. 28, 1911.

5 SHEETSSHEET 5.

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barman sears PAEENT caries.

HENRY E. WALLIS, 0F TERRE HAUTE, INDIANA.

FURNACE.

aesaso.

To all whom it may concern:

Be it known that I, HENRY E. \VALLIs, of 'lerre Haute, in the county ofVigo and State of Indiana, have invented certain new and usefulImprovements in Furnaces, of which the following is a specification.

This invention relates to furnaces and the fuel-feeding means thereofand has for its important objectsto provide improved. and efiicientmeans for supplying solid fuel to furnaces in an automatic manner by theaid of a blast of steam or other suitable fluid fuel element underpressure which scatters fuel properly over a rotating grate; andadapting the device for use in connection with furnaces of ordinaryconstruction without material change. Owing to the blast fuel feed, therotation of the grate, and their relative location, the fuel isautomatically deposited at different points on the grate surface wherebyover-stoking at any one point is avoided and the fuel throughouttheentire grate surface is maintained in an incandescent state.

A furnace embodying the present improvements is illustrated-in theaccompanying drawings, in which Figure 1, is a front elevation of thefurnace, partly in section to illustrate some of Fig. 2, is a detail ofdevices for controlling the blast. Fig. ,3, is a detail sectional viewshowing one bearing for the ash-conveyer. Fig. 4, is a detail of thecorresponding end of the screw conveyer-shaft.'

Fig. 5, is a longitudinal vertical section of the furnace. Fig. 6, is adetail of the bullring and ash-ring. Fig. 7, is a horizontal section ofthe furnace. Fig. 8, is a detail view of the solid fuel feeder. Fig. 9,is a detail view of a portion of the driving mechanism for the rotatinggrate. Fig. 10, is a vertical section through the feed hopper. Fig. 11,is a detail view of the connection between the grate-supportingtruss-bars. Fig. 12 is a diagram illustrating, in plan, the relationbetween the grate and the feeder.

The improvements are shown in connection with a steam boiler furnace,for which they have special and characteristic advantages, but they areapplicable to furnaces for other purposes; it being, however, necessaryfor the purposes of the invention to have at hand some suitable sourceof fluid under pressure such as steam, air or gas for producing theblast which injects the fuel into the furnace. In the example shown inthe Specification of Letters Patent.

Patented Feb. 28, 1911.

Application filed January 8, 1907. Serial No. 351,349.

drawings this blast is produced by steam drawn from the boiler A,through pipe a, which, as shown, may be provided with a valve 7), whichis automatically actuated to periodically or intermittently permit thesteam from pipe (1, to enter a perforated blast pipe B. This blast pipeB, is arranged, as shown in Fig. 5, directly above a throat C, fittingin one of the usual stoking apertures at one side of the furnace(Fig. 1) and communicating at its inner end with the fire-box orcombustion chamber D, of the furnace and at its outer end havingcommunication. with the side outlet of a feed hopper E, in the roundedbottom of which is fitted a screw conveyer or feeder F, which, whenrotated, causes the solid fuel'in the hopper to move inwardly and overthe throat G, beneath and in front of the blast pipe B. which whensupplied with a blast of steam by the valve b, will inject the solidfuel in front of it into the furnace and seatter the same upon the grateG. The fuel is ulpported in front of the blast pipe B, or in t er words,between the blast pipe and the fire preparatory to-its injection, by thebottom of the throat C. The solid fuel rests momentarily in front of theblast-pipe within the fire-box before being scattered upon the grate,and hence is subjected to a sufiicient degree of heat to evaporate anymoisture remaining therein and to partially evolve the gases of thefuel, a result greatly beneficial to combustion.

It is desirable that the solid fuel used be more or less comminuted inorder not. only that it may be more easily acted upon by the steamblast, but that its combustion in this state will more readily takeplace and it may be more evenly distributed over the surface of thegrate. the hopper E, may be reduced to the desired degree of fineness inany suitable way, but in order that large lumps may be automaticallybroken up after introduction into the hopper and reduced to a sufficientdegree of fineness to be blown into the fire by the blast, specialmeans, hereafter specified, are employed.

As the fuel is injected into the furnace the grate G, is graduallyrotated to present fresh surfaces of its incande scent fuel bed forreceiving the successively depos ted solld fuel and thus bysimultaneously rotating the grate and injecting the fuel, the fresh fuelis injected onto live coals and the fuel The fuel deposited for use inmaintained in an incandescent condition throughout the entire gratesurface is thus and state of perfect combustion. Special means forrotating the grate are hereinafter described.

Owing to the characteristics of the graterotating means, the portion ofthe 'ate which is on the same side of the longitudithroat of the solidfuel feeder and the fluidv the grate.

coming stream of solid fuel.

fuel blast pipe. The mechanical feeder for the'solid fuel and the fluidfuel blast pipe, which together constitute a blast fuel feed, being atone side of the center of the grate and in front thereof, project thefuel tangentially with respect to the grate and not radially toward thecenter thereof. As the result of this arrangement the solid fuel isprojected by the fluid fuel blast upon the traveling and advancing livefuel bed upon The solid fuel is thus deposited in a fine stream uponsuccessively fresh portions of the live fuel bed which are in a highlyheated incandescent state, and as fast as the fresh solid fuel fallsupon the live fuel bed the rotation of the grate carries the fresh fuelbeyond range of the in- The combustion of the solid fuel in the side ofthe firebox remote from the blast fuel feed causes the presentation ofan incandescent or live fuel bed to receive the depositof the stream offresh fuel. There is therefore present the most effective conditions forthe complete combustion of the solid fuel.

Owing to the fact that the solid fuel is deposited upon a grate, whichhas passages between the grate bars for the downward passage of ashesand the upward passage of air, provision is thereby made for thedischarge .of the ashes and the admission of air to support combustion.

The air in passing through the grate and. the live fuel ed is therebypreheated to proper temperature to promote complete combustion, Thefluid fuel (preferably steam, particularly with steam-boiler furnaces)not only projects the stream of solid fuel upon the grate but also is afuel element and it is ejected into the fire chamber above the live fuelbed where it is heated to the required temperature and mixes with asesrising from the freshly delivered solid fuel and facilitates combustion.

The result of this combination of a blast fuel feed and a rotary grateis high eiiiciency and the substantial elimination of smoke.

The mechanically operated feeder for the solid fuel and the rotatinggrate are actuated by connected mechanisms, thus securing a properrelation between the feed of the fuel and the travel of the fuel bed onthe grate so that the fresh fuel is fed tated once in about six or'seven minutes;

and should be supplied with fuel at the rate of five or six charges aminute, in case the intermittent blast is used. In case low gradebituminous slack coal is used, each charge should be about one and ahalf pounds in weight. Itwill be found eflicient to use steam at apressure of from fifteen to twenty pounds per square inch at theblast'pipe B.

' The power of the mechanism may be received from any suitable, source,and a main drive shaft is shown at 10. This main shaft has a worm 11(shown in Figs. 1, and 5), which engages a worm-wheel 12, on theshaft'of the solid fuel feeder F. This feeder F, extends horizontallythrough the hopper E, toward the throat C. a It is in the form of aspiral conveyer. In order to reduce to proper degree of fineness anylumps of fuel which may be deposited into the hopper, the edges of theconveyer are provided with teeth (3, which engage such lumps and forcethem against ribs 0, arranged above the bottom of the hopper E. see Fig.8) and intermeshing for-actuating the various parts with the fiig ts ofthe'.c0nveyer, the purpose of the said ribs being to hold the lumpsaloof from the bottom of the hopper while they are impinged at anintermediate point between the ribs by the teeth (Z, and thus brokeninto two or more pieces. A. tooth d, is formed at each turn of thespiral rib of the feeder F and each tooth has a substantially radialface which faces forward in the direction of rotation of the feeder. Thebottom of the hopper constitutes a channel in which the rotary conveyeror feeder turns. The discharge throat C, extends from the inner end ofthe hopper beyond the conveyer or feeder F, so as to provide asupportfor a charge of fuel preparatory to its injection into thecombustion chamber. To facilitate access to the spiral solid fuel feederF, the mouth f, of the hopper is arranged to swing upwardly as indicatedin dotted lines in Fig. 5.

The fluid fuel element (such as steam) may be a continuous blast; but,preferably, it is intermittent. valve 6, is employed between the feedpipe a, and the blast pipe B. Any suitable form of valve may beemployed, and there is-,in-

To this end a suitable eeaeso worm 11, cooperates with a horizontallyarranged work wheel 17, (see Fig. on the shaft of which is a wheel 18.This wheel 18, as shown in Fig. 2, has a laterally extending hunter 19,which, at each revolution of the wheel 18, is adapted to strike alaterally projecting arm 20 on the stem 13, of the puppet valve 7). Thispartly rotates the stem 13, and hence the valve is lifted through theco-action of the cams 14, and 15. As soon as the hunter 19, releases thearm 20, the spring 16, closes the valve. Tn this manner an intermittentblast of fluid fuel is furnished.

The rotary grate is composed of grate sections g, each of sector shape,and each having a plurality of separate grate bars furnishing air spacesfor the upward passage of air from the ash-pit H, beneath throughthefuel on the grate to the combustion chamber D, above, and alsoproviding for the downward passage of the ashes. The outer margins ofthe grate sections are supported upon an annular bull-ring I. Thisbull-ring has integral loops h, with which lugs on the grate sectionscooperate, as shown in Fig. 5. The inner ends of the grate sections aresupported upon a trussspider consisting of truss-bars 5, which meetatthe center and cachof which has at its outer end a bent end to engagean integral loop T, on the bull-ring. This construction of rotatinggrate involves the minimum obstruction on the underside of the grate.The lower edge of the bull-ring is stiffened by a ratchet-ring K, boltedthereto having ratchet-teeth on its outer periphery. This ratchet-ringcooperates with a driving spring-controlled pawl L, which is pivotallymounted upon a swinging sway-bar M, pivoted at its middle at 21, asshown in Figs. 5, and 7. The outer end of the sway-bar has alongitudinal slot 22 (see Fig. 7), in which enters a bowl 23 (see Fig.9), carried on the underside of the wheel 18, as shown in Fig.

2. Consequently, the rotary grate is advanced one step at each rotationof the wheel 18.

It is important that the grate should always rotate freely and easilyand in such a way as not to be affected by accumulating ashes. To thisend the construction illustrated is employed. The bull-ring T, islocated wholly beneath a fixed dead-plate N, and the dead-plate is asclose to the bullring as free rotation will permit. The bullring isrotatively located upon a fixed ashring 0, and the construction ofash-ring and bull-ring is such as to provide a race-way foranti-friction balls P. As the result of this construction the bull-ringturns on ball bearings and hence is readily and easily rotated. The ballrace is provided by the cooperative constructions of the bull-ring andash-ring respectively, as'best shown in Fig.

6. The bull-ring has a horizontal flange m, an inner vertical walln, andouter vertical wall p. Similarly, the ash-ring O, has a bottom 7, innervertical wall 8, and outer vertical wall If. The halls rest on thebottom 1', of the ash-ring and the flange m, of the bull-ring rests onthe, balls. As shown in Fig. 6, the outer wall t, of the ash-ringextends above the center of the balls; while the inner wall of thebull-ring extends below the center of the balls. This is an importantfeature, taken in connection with the vertical character of these walls,since it prevents the climbing up of the balls, due to their outwardthrust, which would cause the bull-ring to bind and hence fail toretate. lVith the construction shown the grate always rotates freely andattention is reduced to the minimum.

The brid o wall as shown in Fi 'exi i tends above the throat C, andabovethe nozzle of the blast pipe and the axis of the mechanical feeder,thus minimizing the danger of any portion of the solid fuel being blownover the bridge wall. To aid in avoiding this blowing over of solidfuel, the blast is downward as well as inward. In order to preventdestruction of the throat by the force of the blast and the presence ofthe comminuted fuel, a hardened steel plate 11, is placed in the throatas shown in Fig. It is importantthat the ashes should be removed as fastas they accumulate in the ashpit H, in order to maintain a uniform airsupply beneath the grate. Accordingly a depressed channel R, is providedbelow the bottom of the ash-pit into which the ashes are swept by meansof the ash sweep S. which is carried by the rotary grate and whichtravels just above the floor of the ashpit. The ashes are continuouslydischarged from the depressed channel B, into a receiver T, at the frontof the furnace (from which place they can be conveniently removed fromtime to time) by a screw ashconveyer U. This ash-conveyer consists ofspiral flights w, mounted upon a rotary shaft V. This shaft is rotatedby sprocket wheels 24 and sprocket chain 25, connecting it with the wormwheel 12. To facilitate the turning of this ash-conveyer, its rear endis supported by ball bearings formed in a sectional casing W, at therear (see Fig. 3), the sectional construction of which enables the balls00, to be located in the grooves 3 correspond to the pitch of theflights of the conveyer. Preferably, also, the flight of the conveyer F,which is nearest the discharge mouth of the hopper, is of slightlygreater pitch than the other flights so as to prevent choking.

Fig. 11, illustrates the preferred plan for connecting the truss-bars J,at the middle of the grate. As here shown, there are four radialtruss-bars which meet at the middle of the grate, and are boltedtogether.

The grate mounting herein illustrated and described constitutes thesubject matter of a divisional application filed September 26, 1907,Serial No. 39L696. I

I claim 1. A steam boiler smoke consuming furnace for burning solid fuelhaving, in combination, a horizontal rotating grate having spaces" forthe passage'of ashes from above and of air from below, a feeder forsolid fuel arranged at one side of the furnace and in front of the gratefor feeding solid fuel to one side of the center of the grate and towardan approaching portion of the grate, and a steam blast-pipe whichdirects a blast of steam into contact with the solid fuel in thedischarge throat of the.

feeder and thence across the approaching portion of the grate and at oneside of the center thereof, said steam-blast projecting the solid fuelwith it and upon the advancing live fuel-bed on the grate.

A steam-boiler furnace having, in combination, a horizontal rotatinggrate, a feeder for solid fuel feeding the solid fuel to one side of thecenter of the grate and toward an approaching portion of the grate, andasteam blast-pipe which directs a blast of steam into contact with thesolid fuel in the discharge throat of the feeder and thence across theapproaching portion of the grate and atone side of-the center thereof,said blast projecting the solid fuel with it and upon the advancing livefuel-bed on the grate.

A steam-boiler furnace having, in combination, a horizontal rotatinggrate, and a. steam-blast fuel-feed which delivers solid fuel to oneside of the center of the grate and upon a live fuel'bed on the grate.

4. A steam-boiler furnace havlng, in combination. a horizontal rotatingrate, and a steam-blast fuel-feed which delivers solid fuel upon a livefuel-bed on the grate.

5. A steam-boiler furnace having, in combination, a horizontal rotatinggrate, a mechanical feeder for solid fuel, connected mechanisms forrotating the grate and driving the feeder, and a steam blast-pipe whichdirects a blast of steam into contact with the solid fuel in thedischarge throat of the feederftherehv projecting the solid fuel ontothe grate.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

ORA D. DAVIS, A. L. lifILLEnl

